Each person took the test twice over two days and beforehand received either an injection of ghrelin, a hunger hormone that is released by the stomach, or a shot of saline as a control.

The expensive version - Lucentis - is about $2000 per injection, and patients may need a shot every 4 to 6 weeks.

The cause of usual molding fault in the course of injection forming, such as the short shot, the viscous flow and the sedimentation tache, was analyzed.